(A) The hazard group for an employer shall be determined as follows. The employer's experience-rated premium for the policy year shall be allocated to the ten industry groups used in experience rating as provided in appendix B, (table 1, part B), of rule 4123-17-05 of the Administrative Code. The industry group producing the most premium shall be used to determine the hazard group, unless that industry group is group ten; in the latter case, the industry group producing the second highest premium shall be used, unless its premium is less than ten per cent. Industry group ten is the determining industry group only if it has the largest premium and no other industry group has ten per cent of premium. If the determining industry group is two, four, five, or ten, the hazard group shall be A. If the determining industry group is six, seven, or nine, the hazard group shall be B. If the determining industry group is one or three, the hazard group shall be C. If the determining industry group is eight, the hazard group shall be D. For all public employer taxing districts, the hazard group shall be that group specifically developed for such employers and as shall be periodically established by the administrator with the advice and consent of the bureau of workers' compensation board of directors.
(B) The Ohio bureau of workers' compensation shall notify the employer of the estimated minimum premium percentage based on the limits selected by the employer and the payroll of the employer. The premium rates on the payroll reports received by the employer for the policy year will be calculated using the minimum premium per cent.